When and how did plate tectonics begin on earth? | EARTH Magazine

When and how did plate tectonics begin on earth? | EARTH Magazine:



'via Blog this'

Grand Falls are flowing

Photos from Daryl and Karen Austermiller's flight over the falls. Note the black lava damn that caused the Little Colorado River to flow around it and form the falls as it returned to its former river bed.

Harry Allen

Evidence for an Old Canyon

the Geology Page presented some of the evidence for an Old Canyon

grand-canyon-at-least-70-million-years-old.html

The debate continues,

Harry Allen

 A new lead zinc silver deposit found in southern Arizona.


http://arizonageology.blogspot.com/2016/09/zinc-lead-silver-mineral-deposit.html


Harry Allen

The geologists are coming

From the AZ geologic survey

 A short geology rap

Harry Allen

Geo tour of Northern Arizona

The Arizona  Geologic Survey posted a  Geo tour of Northern Arizona -- A virtual Field trip

Geotour

Check it out

Harry Allen

airplane geology

On your next flight --find out the geology of flyover country/

rocks from above

Harry Allen